Importazole is a selective inhibitor of the nuclear import receptor importin-β, making it a valuable tool in cell biology research. It is primarily used to study nucleocytoplasmic transport mechanisms by blocking the import of proteins containing classical nuclear localization signals. Researchers use importazole to investigate the role of nuclear import in processes such as gene expression, cell division, and viral infection. Due to its ability to rapidly and reversibly inhibit nuclear transport, it is also employed in live-cell imaging experiments to observe real-time changes in protein localization. Its specificity and cell permeability make it ideal for probing the functions of the importin-β pathway without broadly disrupting other cellular functions.